A Very Good Brother
by lumixedia
Summary: Why would 13-year-old Mycroft have been entrusted with the truth about his sister when his parents were not? What would Mycroft have thought of John's new girlfriend, Mary? Was Mycroft telling the truth when he denied being "given to outbursts of brotherly compassion"? What was going through Sherlock's head as he pointed a gun at his brother? Four dialogues.
1. Rudi

"I'm so sorry…she didn't make it."

The Holmes family was gathered in their new living room, which, after two months, still felt cold and unwelcoming compared to the burned one at Musgrave. Uncle Rudi quietly described the circumstances of the fire in which Eurus had perished, watching grimly as Mr. and Mrs. Holmes huddled together on the sofa in pain and horror, whispering her name in broken voices. Little Sherlock stood in a corner, utterly still, face blank and eyes unfocused, seemingly unaware of Rudi's words, his parents' sobs, or for that matter anything else in the world. Thirteen-year-old Mycroft perched at the tip of a tall wooden chair, as still and emotionless as his brother. But where Sherlock appeared insensate, Mycroft was coiled with alertness, staring at Rudi with a predator's eyes.

When Rudi had said everything he could and gotten up to leave, Mycroft waited until he'd closed the front door behind him. Then he glanced around quickly, concluded that nobody in the room would notice his disappearance in their current state, and slipped out after his uncle. He ran to catch up and got to Rudi just as he was about to get in his car.

"Yes, Mycroft?" Rudi asked uncertainly.

"You-liar," Mycroft panted, winded from the unexpected exertion. "You-dirty-rotten-liar. I know she isn't dead."

Rudi's eyes widened in alarm. "Denial is a normal part of the grieving process-"

"Shut _up_ ," Mycroft snapped. "I know where you sent her. She's at an island prison named Sherrinford and she's alive and well. I found the papers."

"How did you-" Rudi stopped without finishing the question and surrendered. Of _course_ Mycroft would figure it out. Dealing with the Holmes children had always been like this. His sister's abstract intelligence and his brother-in-law's good common sense had proven a remarkable and frankly toxic combination, three times over. "I lied for a good reason, Mycroft. You must keep this a secret."

"What good reason could there possibly be for-for-" Mycroft gestured furiously at the house behind him, with its living room smothered in grief.

"Tell me, nephew mine," Rudi said softly, "how much did you learn about Sherrinford when you were spying on me? Did you see the names of the other people locked there? Did you read the rules governing what human contact the prisoners may have? Did you find out that most likely none of you will ever be allowed to see her, that every word of correspondence you exchange will be carefully examined and edited, and most of them will be ultimately blocked from reaching their intended recipient even if nothing nefarious can be found? Did you realize exactly how they plan for her to spend the rest of her childhood and the rest of her life? Knowing that she is alive, under such circumstances, will cause your family far more pain than what they are feeling now. It is better that they accept that they have lost her, because they _have_ lost her, alive or dead. It is better that they believe this and move on."

"You are _wrong_ ," Mycroft said hotly. "I know everything you said, and it's better than thinking my sister is dead. I'd rather be able to exchange five words with her than none. I'd rather spend my life trying to convince the Governor of Sherrinford to let me see her than think there is nothing to see."

"Then consider this," Rudi said. "Your sister is not harmless merely because she is locked in an island fortress. At five years of age, she is capable of a level of psychological manipulation that ruins almost anyone who comes near her and that even you and I, who understand her best, are only moderately resistant to. It is clear enough what she wishes to do to you, your brother, and your parents with her powers. Already your brother's friend is dead and your whole family would have been burnt to a crisp in your home if it hadn't been for sheer luck. You know if your parents know she is alive, they will do anything to speak to her, no matter the cost. Do you think that is worth the risk? If so, do you think it will still be worth the risk when she is an adult?"

Mycroft stared at Rudi, fists clenched. They stood silently for a long time. Slowly, Mycroft released his fists, lowered his eyes, and sighed.

"No," he whispered. "I can't let her hurt them."

"I'm sorry," Rudi said.

Another long silence. Mycroft seemed to come to some kind of resolve. He looked up again, the fire back in his eyes. "I can't let her hurt them, so I will keep your secret. But, mark my words, I will find a way to speak to her."

"The Governor of Sherrinford won't let you."

"If all else fails, I will _become_ the Governor of Sherrinford."

Rudi smiled for the first time all day-actually, quite possibly for the first time all month. "Oh, nephew mine," he said gently. "You are a very good brother."

"No, I am a _horrible_ brother," Mycroft snapped, and stalked off before Rudi could figure out how to reply.


	2. Mary

"Rosamund Teimano."

Mary Morstan froze at the sound of a name she had hoped never to be called again. In a single smooth motion, she slipped her hand into her purse and turned around deliberately to face her interlocutor, who had pulled up next to her in a sleek black car-

"Mr. Holmes!" Mary laughed, relaxing and letting go of her weapons. She had never met Mycroft Holmes, but she had seen pictures of him, both in the course of her work and in the possessions Sherlock Holmes had left with John. "What brings you here?"

"I'd like a word with you," Mycroft said, gesturing at the car door. "Would you get in?"

Mary opened the door and climbed in without hesitation. If there had been any trouble between her and the British government, she wouldn't have returned here. "I am on my way to an appointment, but go ahead."

"I'll be quick." Mycroft did not look at her. He kept his eyes fixed on a point past the windshield, in the far distance. "You have entered into a serious relationship with Dr. John Watson. He has not succeeded in driving you away, unlike countless previous women. His past association with my brother does not frighten or threaten you."

"Sherlock sounds wonderful," Mary said. "I'm sorry for your loss. I wish I could have met him."

Mycroft continued staring at the place where the horizon would have been without the buildings in the way. "Dr. Watson was my brother's best and only friend. He is the reason Sherlock survived as long as he did. He has been a...valuable and remarkable asset." Now he finally turned to meet Mary's eyes. "Rosamund Teimano," he said softly, injecting the faintest hint of menace into his pronunciation of her name, "it is very important to me that he be kept healthy, happy, and safe. You must take good care of him." _Because Sherlock will need him again in a year_ , he thought but could not say.

Mary laughed warmly. "Oh, this is one of _those_ conversations! I never picked up from John that Sherlock's scary brother was so _sweet_."

"I am not being _sweet_ ," Mycroft snapped. "I'm looking after my assets. It's a basic principle of good governance."

Mary laughed more. " _So_ sweet." Then her tone changed, becoming utterly serious even as it retained its warmth and joy. She touched him gently on the shoulder. "I swear, Mr. Holmes, that I will protect and care for John with everything in my power, in all the ways I can, for as long as I possibly can. I swear it on the old name you insist on calling me and all the others I've had before and since."

"Good," Mycroft said, Mary's infectious warmth creeping into his tone for the first time. "Thank you. That's all I wanted to hear."

Mary smiled and turned to open the car door. "Whatever John says," she declared as she stepped out, "you must have been a very good brother."

Mycroft sighed. _I don't think either of my siblings would agree with you_ , he thought as he watched her walk away.


	3. Eurus

When Mycroft entered Eurus's cell, he didn't begin speaking right away. Instead he checked all the cameras and sensors, making sure not only that they would not record the conversation, but that, if examined, they would play back appropriate counterfeit footage with every sign of authenticity.

"Good god, brother, what are you doing?" Eurus exclaimed. She was genuinely surprised. This would have been perfectly normal behavior coming from literally anyone else she communicated with, but _Mycroft_? Mycroft _never_ broke the rules. It was one of his numerous intensely irritating traits.

Mycroft ignored her until he'd finished double-checking every recording device in every corner. He was very thorough, another irritation. But finally he finished, turned to her, and said, "Eurus, I need your help. It's about Sherlock."

" _You_ are coming to _me_ because of _Sherlock_?" This was, quite simply, the most surprising thing that had ever happened to her. She was _never_ surprised. Especially not by her irritating older brother.

"He just shot Charles Augustus Magnussen in the head in front of an entire team of police. It was quite justified, but there is no chance the government will permit him to go unpunished. They are entirely set on sending him to his death in a foreign nation." Mycroft spoke in a flat, matter-of-fact tone, his face and body giving absolutely nothing away.

Of course, Eurus could see right through him. Having gotten over her surprise, she regarded her brother with excited amusement. What he didn't realize was that she had been brainstorming ways to get Sherlock's attention, and that he had just handed her on a silver platter an opportunity far grander and more hilarious than all the alternatives she'd considered. _And_ he was in an emotional state perfect for a little sisterly torment. It really was Christmas.

She would start simple. "And why," she asked, voice high and mocking, "should I care?"

"I know you care," Mycroft replied evenly. "I know you still think you'll get a chance to play your own game with Sherlock one day, and you'd hate to see him taken out before it's your turn."

Eurus giggled. It was so cute, how Mycroft honestly had no idea how close she was to having her challenge to Sherlock ready. All she needed was an extravagant gesture to begin with. "Oh, yes, don't you worry, Sherlock and I will have _so_ much fun," she said, singsong. "You, though, you know I don't need you. You know _we_ don't need you, Sherlock and I. You were always the one that nobody needed. Too old for us, too grumpy for Mummy and Daddy, too chubby for everyone."

Mycroft continued to keep every trace of micro-expression off his face, which was proof that the knife had gone in.

"The point is," Eurus continued, "no amount of video-tampering will save you if I tell your employers about your treachery."

Mycroft held her gaze, steady as a great tree in the gathering wind. "I think you believe that I am more useful to you in the center of the British government than disgraced and in jail. And if I'm wrong...Sherlock will still be safe."

"Oh, are we playing the selfless big brother again? How old. How repetitive. How _tiresome_. Do you ever wonder what it is you're trying to prove to yourself when you act like this? When you obsess over Sherlock's every little scrape and boo-boo, when I ask for a violin and you give me a Stradivarius, what are you hoping to buy?"

Mycroft wouldn't respond. "I can tell you've decided to help. Get on with it."

Eurus rolled her eyes. "Really, the answer should be obvious even to you, if only your mind weren't so tied up in the law-abiding straitjacket."

"Give me a hint."

" _Fine_. Your bosses want to send Sherlock away because they think they no longer need him. You have to show them just how much they still need him."

Mycroft stared. She could almost hear the creaks of the gears turning in his head, painfully processing the kind of solution he never, ever considered. "Bring back an enemy that-that only he can deal with," he said slowly. "Moriarty."

"You have interrogation videos," Eurus said. "You have access to the whole nation's broadcasting infrastructure."

"If I could put Moriarty on every TV screen-" Mycroft murmured. "I don't have that much access. Not enough to slip it in undetected."

Eurus beamed. "I can help with that," she said, and told him how.

It was done. Brother and sister gazed at each other across the reinforced glass, which Mycroft did not know could now be removed as easily as a sliding door, and wondered at the strange and unexpected things that lurked behind each other's eyes.

"You're more alive than I thought," Eurus said, smirking. "Perhaps we'll include you in our game after all."

Only now did Mycroft dare allow expression-specifically, a scowl-back on his face. "There will be no game," he said, "except over my dead body." He turned to leave.

"I wonder," she called out after him, mostly to frustrate him but also slightly because it was true, "whether things could have been different if I'd known this when I was five."

"Known what?" he asked, not turning around.

"That just occasionally, at the oddest times, you can find it in yourself to be a very good brother."

Mycroft froze briefly at her words, seemed to shake them off, and walked away.


	4. Sherlock

After an extraordinary (if unsurprising, under the circumstances) period of chaos, they were finally alone, standing outside Mycroft's house, where Sherlock, John, and Mrs. Hudson were temporarily staying. It was night. There were unusually many stars.

"I never got around to apologizing for pointing a gun at you," Sherlock remarked.

"I would prefer you didn't," Mycroft said, irritated. "There's nothing to apologize for."

"I never for a moment intended to shoot you. I figured that if I didn't make a choice, she might get impatient. I wanted more time to think of alternatives."

"Really, Sherlock, stop it," Mycroft sighed. "It doesn't matter at all."

"Of course it matters. How can it not matter?" Now Sherlock was frustrated too. "After that-ordeal, how can you still be like this?"

"It doesn't matter because if you hadn't thought of a way out you would still have had to kill someone, and if you had had to kill someone it would still have had to be me, and if you had had to kill me it would still have been a perfectly correct and rational decision and nothing worth apologizing for. So don't."

"If I hadn't-it would still-" Sherlock stumbled uncharacteristically over his words. "If she had really insisted on taking one of you-I don't know who-I don't know who it would have been."

"What are you talking about?" Mycroft shot a confused glare at his brother. "It would have been me. You need Dr. Watson, you don't need me. Which is fortunate, because it will be a very dark day indeed when you find yourself so desperate as to have to rely on me. Why are we relitigating this? We're not in that room. The last thing I want to do is go over this again."

"Oh, brother mine," Sherlock breathed, looking at Mycroft with bright eyes and sudden warmth in the lines of his mouth. "I didn't point the gun at you because I need you less. I pointed the gun at you because I knew you could handle it better."

"Sherlock, are you high?"

"Both you and John are long since accustomed to saving my life, but only one of you is accustomed to ingratitude in response. John wouldn't have blamed me, but he would still have been hurt, secretly, deep down inside. But you, look at you, you don't even care. You think this is what big brothers are _for_." Sherlock smiled radiantly.

"Stop it." Mycroft felt something tighten in his chest, something not exactly unpleasant yet still too painful and terrifying to bear. "Enough, brother mine. Stop it."

"I won't stop it. I've meant to say it my whole life but I thought it didn't need to be said. But if you really thought your little trick might work, if you thought anything could make losing you easier, then I was wrong. I need to tell you, out loud, in words, at least once."

"Tell me...what?"

Sherlock put his arm around Mycroft's waist, pulled him close, leaned his head on the elder Holmes's shoulder. Mycroft startled a little, but slowly relaxed against him, even as the tight thing throbbed in his chest. It was the most affection they'd shown each other since an almost-forgotten childhood. "You," Sherlock murmured into the rough fabric of Mycroft's suit, "are a very good brother."

Mycroft didn't reply for a while. When he finally could, he whispered, "You make it worthwhile."

They continued to stand outside, gazing at the stars.


End file.
